Chart: What's the real unemployment rate?

This is how the monthly jobs report is calculated

The U.S. Labor Department said Friday that the unemployment rate was 5.5 percent in March—but does that rate tell the real story?

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A number of economists look past the "main" unemployment rate to a different figure the Bureau of Labor Statistics calls "U-6," which it defines as "total unemployed, plus all marginally attached workers plus total employed part time for economic reasons, as a percent of all civilian labor force plus all marginally attached workers."

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In other words, the unemployed, the underemployed and the discouraged—a rate that still remains high.

The U-6 rate fell in March to 10.9 percent, the first time it has been below 11 percent since Aug. 2008.

The trend in U-6 has been somewhat more volatile than in the main unemployment rate as well. The U-6 rate is down 170 basis points over the last year, versus a 110 basis point decline in the main rate (also known as U-3).

The U-6 rate has held firm in the double digits since June 2008. It most recently peaked at 17.1 percent in April 2010.